The use of rust preventatives in coatings for iron containing alloys such as, for example, various types of steels is well known. Many of these compositions contain phosphoric acid and/or salts thereof. It is also common to include in such compositions resins such as polyacrylates to provide a substantive coating. While these compositions are useful in preventing or reducing the rusting in steels (as described in U.S. Pat. Nos. 3,185,596; 4,183,772 and 4,373,968), the use of these compositions is not free from such problems as instability of the preparations and difficulty in obtaining uniform coatings. Furthermore, these compositions, although useful rust inhibiting precoats before the application of siccative coatings, have poor lubricant properties.
It is, accordingly, an object of this invention to provide rust preventative compounds which are water-soluble and which can be applied in aqueous compositions.
It is a further object of this invention to provide rust preventative compounds which will react with the steel substrate on drydown after the application thereto.
It is another object of this invention to provide rust preventative compositions which form rust preventative films on the steel substrate which on drying are non-oily and non-irritating and which are acceptable in the food processing industry for incidental contact with foods.
It is still another object of this invention to provide rust preventative compositions which can be applied on wet surfaces of steel and which exhibit little or only moderate foaming during application.
It is still another object to provide a film which is rust preventative, is water repellant, and which exhibits lubricating properties.
Other objects will appear in the description which follows: